Project boat issue with photo’s

[gary111160]

My latest winter project has 2 x Yamaha 150hp 2 stroke outboards from 1996. I’ve noticed it doesn’t have any remote oil tanks to feed the tank under the engine cowling. This must surely affect the running range? It’s a two owner boat and I don’t think it’s ever been fitted with them. Anyone have any experience of these engines or helpful comments? Photos attached for info.

 

[Bilgediver]

Some people seem to remove them and revert to mixing in the fuel cans. Go to Ebay and you might be able to buy some and fit them.. Just hope that the pumps are not faulty.

 

[gary111160]

Some people seem to remove them and revert to mixing in the fuel cans. Go to Ebay and you might be able to buy some and fit them.. Just hope that the pumps are not faulty.

Thanks for comment. No pump fitted only what’s fitted to the small tank under the engine cowl. That all seems fine. I can buy a complete kit for each engine at a price! If needed. Would rather run it with proper injection mix than jerrycan. Tank holds 400 litres.

 

[Restoration man]

I bet that thing shifts

 

[gary111160]

I'm hoping so! quite a bit of work to do before sea trial which will likely be next season now.

 

[Wing Mark]

My latest winter project has 2 x Yamaha 150hp 2 stroke outboards from 1996. I’ve noticed it doesn’t have any remote oil tanks to feed the tank under the engine cowling. This must surely affect the running range? It’s a two owner boat and I don’t think it’s ever been fitted with them. Anyone have any experience of these engines or helpful comments? Photos attached for info.

Many years ago I had some 2 stroke motorbikes.
The premix ones generally ran at 50:1,
The oil injection ones generally got through a lot less oil per tank of petrol.
So if the tank under the cowling holds a couple of litres per engine, I reckon it's good for a few hundred litres of petrol.
Obviously it's quite important to check the 'oil low' switch can be trusted absolutely!
And to check the oil level before every outing.

 

[gary111160]

Many years ago I had some 2 stroke motorbikes.
The premix ones generally ran at 50:1,
The oil injection ones generally got through a lot less oil per tank of petrol.
So if the tank under the cowling holds a couple of litres per engine, I reckon it's good for a few hundred litres of petrol.
Obviously it's quite important to check the 'oil low' switch can be trusted absolutely!
And to check the oil level before every outing.

Thanks fo that. The tank under the cowling holds 0.9 litre. But on checking the fuel filter the fuel is coloured so must be pre mixed in the tank or I would have expected clear petrol?

 

[Wing Mark]

Thanks fo that. The tank under the cowling holds 0.9 litre. But on checking the fuel filter the fuel is coloured so must be pre mixed in the tank or I would have expected clear petrol?

Coloured as in blue, green or red? i.e. a colour you'd expect 2T oil to be dyed, not a manky brown or something?
I expect either the previous owner didn't trust the oil injection system, or put extra oil in the fuel for running in., or 'just to be safe'?
Certainly remember some characters with 2 T bike who added a bit to the tank.
The down side is, you may oil the plugs if you do much slow running or repeated starts without getting up to temperature.
2 Strokes In My Limited Experience thrive on moderately hard use.
The person I know who had most trouble with a 2 stroke bike was commuting in traffic and never giving it enough stick.

Your fuel bill scares me!

 

[northwind]

The problems with the remote mixing is if it goes wrong your engines are toast, which is why many did away with them. As others have said, I would premix on older engines, to ensure they don't run without oil as you have no warning if the oil injection fails.

 

[ChromeDome]

Thanks for comment. No pump fitted only what’s fitted to the small tank under the engine cowl. That all seems fine. I can buy a complete kit for each engine at a price! If needed. Would rather run it with proper injection mix than jerrycan. Tank holds 400 litres.

There would be dosing pump somewhere on the motor to facilitate the oil mix (variable?). When these fails you have no lube at all unless a mix in coming from the fuel tank.
If mixing in the tank, the empty oil tank under the cowling might issue a level alarm. Fill oil in that too to solve it.

If interested, a manual can be found here
Yamaha Outboard Owner Manuals | Yamaha Outboards

 

[gary111160]

Thank you all for your comments. I've looked again today under the cowling and the oil tanks on those have also been removed so it clearly is mixed in the tank.I can live with that and it does mean I need not worry about the engines ever being starved of oil.The normal mix according to the manual is 50:1. Do you think I should use that ratio in the fuel tank mix? I also noted different sparplugs to those recommended! Could that be due to the oil fuel mixed in the tank? Engine plate says NGKB7HS-10 but has NGKR BR9HS-10

 

[Wing Mark]

https://www.ngk.com/ngk-spark-plug-numbering-systems

A number 9 NGK plug runs colder than a 7, so it's not been changed to help burn off oil.
(well they might have intended that and got it wrong! IIRC Champion numbers work the other way, confusion is not unknown!)
The R means resistor, to reduce interference.
I've had 2 strokes which are very fussy about plugs.
There may be whizzy modern plugs which are better than was recommended back when these engines were new?
If the plugs look healthy and don't oil up, I'd run with them, but always carry spares.

But then again:
https://www.ngk.com/what-ngk-plugs-should-i-use-with-marine-cdi

And searching for plugs for a 96 150 Yam gives:
https://www.ngk.com/ngk-1098-br7hs-10-nickel-spark-plug
The NGK site has a look-up.

 

[Rappey]

Had a mariner 90 ,low hrs, looked after totally destroyed because of a failure in the oil injection system. Will always premix oil and fuel nowadays.

 

[gary111160]

https://www.ngk.com/ngk-spark-plug-numbering-systems

A number 9 NGK plug runs colder than a 7, so it's not been changed to help burn off oil.
(well they might have intended that and got it wrong! IIRC Champion numbers work the other way, confusion is not unknown!)
The R means resistor, to reduce interference.
I've had 2 strokes which are very fussy about plugs.
There may be whizzy modern plugs which are better than was recommended back when these engines were new?
If the plugs look healthy and don't oil up, I'd run with them, but always carry spares.

But then again:
https://www.ngk.com/what-ngk-plugs-should-i-use-with-marine-cdi

And searching for plugs for a 96 150 Yam gives:
https://www.ngk.com/ngk-1098-br7hs-10-nickel-spark-plug
The NGK site has a look-up.

Thanks for the info and links. I'll pull the plugs and see what condition there in.